Filter construction.



G. F. HODKINSON.

FILTER CONSTRUCTION.

APPLICATION FILED JULY 16 1912.

Patented Ocfi. 27, 1911 2 SHEETS-SHEET 1.

WITNESSES A TTORNE Y G. F. HODKINSON. FILTER CONSTRUCTION.

APPLICATION FILED JULY 16, m2.

Patented Oct. 27, 1914.

2 SHEETS-SHEET 2.

Flt; .5-

IN VE N TOR WITNES SES I BY @Z /MM 41W @Wu W4, 4 W

A TTORNE Y .ing operation.

UNITED STATES PATENT OFFICE.

GnonenmaonmNsoN, 9p; r-HILA ELP HIA, PENNSYLVANIA, ASSIGNOR or ONE-11am: T0 AmnicAN-wA'raasomENEn coMPANY, or PHILADELPHIA, PENNSYLVANIA,

A CORPORATION OF- NEW JERSEY.

FILTER coNs'rRUc'rI'oN.

Specification of Letters Patent.

Patented Oct. 27, 19.14.

Continuation in part of application .Serial No. 682,974, filed March 1 1, 1912. This application filed July 16,

1912. Serial N6. 709,679.

To all whom it may camera Be it known that I,"Gsonen F. -HODKINSON, a citizen of the United States, residing at School Lane and Pulaski avenue, Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented, a certain new and useful Filter Construction, of which the-following isa specification.

The purpose of my'invention is agitation, aeration and cleansing of gravel-filled .filter conduits covered :w'ithsa'nd, and protection of the gravelagainst displacement by. the currents of;air and, at/erased.

A further purposefif ny' invention is to separate gravel or] bther filter bed material from the filtering a. l a screen and introduce air "a under pressure beneath this screen i A further piir 0s maintain gravel prevent sand in y; ention is to t. n i'n a filter and the interstices the gravel vity filter by different sizes Further purpose specification and thereto. 5 I have prefer us trat fe' my inven tion by formsther wh ch l'have found to be practical, efficient! and relatively inexpensive, and which'well illustrate the prin ples involved f I Figure 1 is a transverse section across the gravel channels showinga part of an open gravity filter to which my invention is applied. Fig; 2 is a partial section of the structure of Fig. 1 taken upon line -00 thereof. ,Fig. 3 is a topr plan view of a por appended vtion-of the'structureshown in F igs l and 2 after the sand and gravel have been removed. Fig. 4:,lS anwnlarged broken section of the structure shownin Fig. 2 upon line y-y thereof.

gravity filter having raw water supply flume 6, filtered water-channel 7, inlet water con nection 8 and filter tank 9, showing concrete walls throughout. Y

The water normally filters down through the sand bed 10 into the gravel 'chann els'll, thence through the perforated plates 12 into the water laterals 13. i It is then drawn off by tneans of the manifold 14' and main collector pipe 1%. connected with the giping 15, i6 and. 17 in the usual way. Ihave illustrated suitable valves, as 18, 19, 20 and 21,

at convenient points. Washing is effected by reversal'of direction of water passage, forcing it through the pipes 14, 15 and the manifold 14 into the waterlaterals, thence which my in- Fig. 5 is a transverse section of an air distributing pipe. used by through the gravel and sand,-.in this order," l

and withdrawing the wash water through wash troughs 22 and a wash fliime into a waste pipe 23 protected by valve 24. ,1

show a rewash connection between the pipe I 14' and the lower part of the waste pipe at 25, with valve 26 therein. The float tube for loss of head age is shown at 27, leading 1 to the control tale 28.

The detail structure of the partichlar :fori'n of filter bottom in connection with which I have preferred to illustrate my invention is best seen in Fig. 4. The concrete walls 29 are provided with tapered openings 30, at intervals, within which pins 31 lie. These pins are surrounded with cement and extend into the lower bed of concrete at 31'. The perforated plates 12 are retained by U or hook bolts 32, passing about cross bars 33 which fit into any suitable recesses 34. This structure Ialso is wn known.

air laterals so as to discharge below the gravel has been recognized but with so little success in overcoming the difliculties that some filters have to be entirely cleaned out at short intervals and others apply air but above the gravel.

I introduce the air by means of laterals 35 which extend longitudinally near the bottoms of the gravel chambers or channels 11 and are apertured at 36, 37, preferably in staggered relation alternating along the length of the pipe, and beneath andat the side of the ducts, the openings being best seeninF' .5.

At thetime that the air is first turned on in such a system as I have illustrated, the air pipes are filled with water. The water is forced ahead of the air out of the vertical pipes and laterals and, last, out of the pipes 35 through the openings 36 and 37, which. are placed in the bottom of the pipe for two reasons: The water naturally settles in the bottom of the pipe and the continued.air pressure is thus enabled to force all of the water out; and the expulsion of the air in divergent .directions downwardly, greatly assists in the distribution of the air and agitation by'it.

- The avel is preferably arranged in layers of 'fl'erent sizes, fine above and coarse below, and, where the gravel lies within channel, I'prefer to form the tops of successive layers higher in'the center than at the edges, as best seen in Fig. 4, for purposes hereafter shown.

The water supplied to bring the sand to fluidity and to rinse it is not required in suflicient volume and pressure to tend to greatly disturb the gravel. But when in addition .the. air is supplied in sufiicient volume and at' apressure deliberately designed to agitate the sand, bu'tfor my invention the combined flows disturb the protecting layer of gravel above the air openings and allow sand to'mix with the gravel in a way which would not occur if the comparatively close assemblage'of the successive layers of graded gravel had not been dis turbed. I

The air pressure is supplied to the laterals by the vertical feeders 38 from manifold 39,- connected with the mainair supply pipe 40 by vertical connection 41. I aim to protect the gravel from disturbance by the combined water and air flow and to combine this protection with a desirable arrange ment of the gravel to obtain the most eflectivedistribution of the air throughout the cloth and referably in the form and having the reliition to the other parts hereinafter described. The screen is shown as covering a gravelchannel in Figs. 1-4 and as covering a gravel bed in Fig. 6.

The use of a cover screen over a gravel channel is not broadly new to me, but .I believe the use of air under' such a cover is new and especially when'fitting against, or nearly against the gravel in a full, or approximately full gravel-channel, and that I am the first to bow the screen and the bed of gravel over an air inlet so asto obtain approximate equality of gravel resistance to the flow of the mixed air and water, in order that they be diverted from a direct u ward course and distributed in substantia y the same lines from each channel within a channel section, agitating at the same time and over nearly the same area, as that rendered fluid by the water. Ihave indicated possible limits for the channel form illustrated,sapproximately represented by the continuation of the side planes of each of the gravel chan nels, as seen in 1 at lines 43, 44, and 43', 44. The exact extent of the diversion of the lines of flow of the water and air will depend upon the pressuresof each, the conditions and depths of the gravel and sand, the shapes of the sides of the gravel channels, and, for the air, the depth at which the air is introduced and the number, size and spacing of theair openings, etc. v

The openings in plate 12 are preferably smaller than in the screen 42 an they are also not quite as close together. Viewed as screens, that appearing in the arched plate at 12 and held against the cement walls by bolt 32 is relatively finer than the screen 42. For this reason, as well as because of the greater area of the screen 42. due to its location at a wider partv of the channel, the screen 42, particularly in the form shown in Figs. 1-4, offers much less resistance to pas beincreased by "the pressure of the air admitted between the screens. p The sum of the areas of the holesv m screen 12 must, of course, beless than the cross sectional area of the wash water supply. The

filling of the gravel channels practically into contact, preferably into close'contact with the wire cloth, prevents the intermingling of the different sizes of gravel and makes each size, in its place, protect the interstices closure, protecting the necessarily of the next larger size below from improper openings of the air late ls from sand interference.

While the arrangementabowe with bowed for bringing screen, is referred for some types oi filter, a part 0 the advantage is obtained by merely the gravel channels up to the top. and placing the wire cloth in substantial contact with the top Qf the gravel, since little room is thus given for movement of the gravel, and onepart of my invention contemplates the use of flat screens, instead of the bowed screens 42 whether the channel be filled up with gravel or not, in such a structure as that shown in Fig. 4 and the preferred use'of flat screens. 42 in other structures of which one form is shown in Fig. 6. The the channel above the level of its sidewa s, preferably in curved formation, affords much better opportunity the wire cloth down against vel with whatever fit thereagainst may. desired by the engineer, in view of the circumstances of the particular installation in mind and-to suit his own preference. It gives, moreover, the desired curvature of the top of the gravel, which, when maintained in. each of the several layers of the difierent sizes of the gravel, secures the best results in the thorough concurrent distributhe tion of the water and air with cross currents from adjoining channels beginning of these at a distance shortly above the tops 0 channels.

I have illustrated the gravel at 45, 4 surfaces 45, 46, 47 and 48, respectively, without intending to suggest this number of sizes, curvature, nor this degree of curvature of surfaces as essential to secure a part, at least, of the benefit of my invention. have secured the wire cloth to the tops of the concrete walls as at 49, by any suitable bolts or other means 50, so as to conform it to the shhpe of the top of the gravel.

In the form shown in Fig. 6, I have applied my invention to a filter in which the gravel lies in extended beds, rather than in channels, and in which the screen cover 42 for restraint of gravel movement is held in place by posts 50, located at intervals, and to which the wire cloth is secured in any suitable way. c

It will be evident that my maintenance of the protection of the ravel enables me to put the air pipes low in the bed, where the airwill mingle with and be carried along by the streams of water, and where it will be further spread by the divergence of the gravel paths. 7

It Wlll be further evident that the pressure of the air may be made equal over the entire system of laterals if the proportion of the aggregate cross-section of the air orifices to .the cross-section of the feeding pipes be kept low. I It will be iurther evident sired, system of water and f the several layers of that any deair feeders or 46, 47, 48, having curved upper headers may be used for supplying the air and water conveniently and effectively.

Having thus described my invention, what I claim as new and desire to secure by Let- 1. In a device of the character stated, a gravel channel, gravel in the channel arranged in graded layers in contact with each other, the finer gravel being at the top, a screen coveri the channel and in substantial contact with the gravel, sand over the gravel and screen, means for withdrawing water filtered through the sand and gravel and means for forcing water into the channel and separate means for releasing air under pressure within the, gravel at a point near the bottom of the channel.

2. In a device of the character stated, a

.ters Patent is gravel channel having sides converging to ward the bottom, gravel filling the channel and extending above the level of the channel walls, a screen cover for the channel, bowed to confine the gravel and to engage with the top of the channel walls, sand above the screen, means for admitting and withdrawing water to and from the bottom of the channel andmeans for admitting air at a point near the bottom of the channel.

3. In a filter, a channel, graded gravel filling the channel, one size of gravel resting upon another, a lateral air pipe within the channel adapted to release air within the gravel, means for supplying air under pressure to the air pipe and means-for maintaining the gravel in graded position against disturbance by the air supply.

4. In a filter, a relatively fine filteringmaterial, a coarser material below the same, a screen between the two materials and means for releasing air within the gravel and water beneath the screen.

5. In a filter, materials of different size therein, one being gravel of different sizes, arranged in layers according to the size, a screen separating the two materials and making contact with the gravel and means for releasing air within the gravel and water beneath the screen.

6. In a filter, a channel, a lateral air pipe within the channel and having openings upon its under side, means for supplying air under pressure to the air ,pipe, a grade filling of gravel for the channel surrounding the air pipe, a screen engaging the top of the gravel for maintaining the gravel in position against disturbance by the air supply and sand above the screen;

' 7. In a filterpa channel, a lateral air pipe within the channel having 0- enings extendin in diverging directions rom the under si e of the ipe, means for supplying air pressure to t e airpipe, a filling of gravel for the channel of difierent sizes and arrahged in contacting layers with the larger sizes beneath the smaller sizes, covering the air pipe and terminating at the top in a convex surface, a bowed screen engaging the convex surface of the gravel for maintaining the gravel in position against disturbance by the air supply and sand above the screen.

8. In a filter, a channel, screens at the top and bottom of the channel, the lower screen being of relatively finer mesh than the upper screen, ofiering more resistance to fluid passage therethrough, gravel filling the space between the screens, Sand above the upper screen, a lateral air pipe within the gravel apertured therein, means for supplying air under pressureto J said air pipe and means for supplying water under pressure beneath the lower screen.

9. In a device of the class described, a filter bottom comprising a water channel, a screen overlying said water channel, an air duct above said screen, a second screen above said air duct, filterin material above said second screen, and re atively coarser material between said first mentioned screen and said second screen.

10. In a device of the class described, a

filter bottom comprising a water channel, a

fine screen above said water channel, an air duct above said screen, a relatively coarser screen above said air duct, material between said screens com osed of parts too large to pass throughnsaid upper screen, and finer filtering material above said upper screen.

11. In a filter, a base or floor, a series of upwardly tapering rojections on said floor, a screen extending etween said projections below the tops thereof, a second screen above said first mentioned screen, filtering material above said second screen and'relatively coarser material between said screens, means for discharging air under pressure into the space between said screens, and means for forcing water into the space below said first mentioned screen for the purpose of causin an upward current of air and water throu i said filter.

12. n a filter, a base or floor, a series of upwardlytapering projections on said floor, a screen extending between said projections below the tops thereof, a second screen extending across the tops, of said projections, filtering material above said second screen and relatively coarser material between said screens, means for discharging air under pressure into the space between said screens, and means for forcing water into the space below said first mentioned screen for the purpose of causing an upward current of air and water through said filter.

13. In a filter, a base or floor, a series of upwardly tapering rojections on said floor, a screen extending below the tops thereof, a second screen extending across'the tops or sald projections, air inlet ipes between said screens, means for introducing water under pressure beneath said first mentioned screen, filtering material above said second screen, and relatively coarser material between said screens. 14. In a filter a base or floor having a series of parallel depressions separated by Walls which taper relatively fine screens extending between said walls below their upper edges an air inlet pipe communicating with said filter above said screens, a coarser screen above said air inlet pipe, filtering material above said coarser screen, relatively coarser mate= rial between said screens, and means for introducing water below said finer screen.

15. In a filter, a base or floor having a series of arallel depressions separated by walls whic taper toward their upper edges, relativel fine screens extendin between said wa ls below their upper e ges, bolts engaging said screens and at their lower ends engaging cross members anchored in the adjolnmg walls, an air inlet pipe communicating w1th said filter above said screen, a coarser screen above said air inlet pipe, filtering material above said coarser screen, relatively coarser material between said screens, and means for introducing water below said finer screen. I

'16. In a filter, a base or floor having a series of parallel depressions separated by wallswhich taper toward their upper edges, relatively fine screens extendin between said walls below their upper e ges, bolts engaging said screens and anchored at their lower ends to the adjoining walls, an air inlet pipe communicating with said filter above said screen, a coarser screen above said air inlet pipe, filtering material above said coarser screen, relatively coarser material between said screens, and means for introducing water below said finer 'screen. 17. In a filter, a'base or floor having a series of ara llel depressions separated by walls whic taper toward their upper edges, relatively fine screens extending between said walls, bolts engaging the central part of said screens and extending downwardly therefrom and at the lower ends engaging cross members anchored in recesses in the adjoining walls, an air inlet pipe communicating wlth said filter above said screen, a coarser screen' above said air inlet pipe, filtering material above said coarser screen, relatively coarser material between said screens, andmeans for introducing water below said finer screen.

18. In a filter abase or floor having a series of arallel depressions separated by walls whic taper toward their upper edges,

etween said projections relativel fine screens extending between said we bolts engaging the central part toward their upper edges,

of said screens and extending downwardly therefrom and at the lower ends engaging cross members anchored in recesses in the adjoining walls, an air inlet pipe communieating with said filter above said screen, a coarser screen above said air inlet ipe, said coarser screen being secured by olts to the upper edges of said walls, filtering material above said coarser screen, relatively coarser material between said screens, and 1' means for introducing water below said finer screen.

GEORGE F. HODKINSON. Witnesses:

HELEN I. KAUFFMAN, WM. STEELL JACKSON. 

